Mobile devices such as smart-phones have increasingly large display screens. The display screen consumes a large amount of power, and operation of the display screen causes the battery of the mobile device to quickly become depleted. For example, a standard display panel for a mobile device can consume around 1 Watt of power when active with normal brightness. In order to reduce battery usage, the display screen is generally automatically dimmed and/or turned off after a short period of inactivity.
The user interfaces of mobile devices are heavily dependent on the display of information to users. Indeed, the user interfaces generally rely on touch-screen technology for receiving user input. In order to use touch-screen input, the display screen must be powered on to display content and virtual buttons for selection by the user, and to detect the user's touch on the screen. The display must thus generally be powered on at any time that information is displayed to the user, and any time that user input is expected from the user.
Visually impaired users of mobile devices, such as blind users, use the touch-screen interface of their mobile devices to interact with the mobile devices. Visually impaired users, however, may not generally require the display screen of their mobile devices to be powered on as they interact with the touch-sensitive input interface. A need therefore exists for enabling visually impaired users of mobile devices to power off the display screens of their mobile devices to as to reduce power consumption. The turning off of the display screen can additionally avoid other persons from viewing information normally displayed on the screen.